Three types of short range missiles, i.e. with a range generally of less than 1 km, are known:                Missiles with homing guidance that can be locked on a desired target (very accurate);        Beam-riding missiles (less accurate than those with homing guidance); and        Inertially guided missiles (less accurate than beam-riding missiles).        
In contrast, projectiles launched in a ballistic trajectory by means of a thrust producing device, such as a bazooka, without guidance control during the flight after launching are relatively inaccurate, and therefore generally have an effective range of up to 300 m.
Several methods have been employed in the prior art in order to improve the accuracy attainable with unguided projectiles:                Reducing the jittering of the projectile launcher by concurrently firing a compensating mass rearwardly from the launch tube as the projectile is fired forwardly therefrom. Launchers which apply such a method are generally referred to as Davis guns.        Using a laser rangefinder for accurately measuring the distance to the selected target, and using the measured distance in order to adjust the angle of the launch tube through which the projectile is fired;        Reducing the drift of the projectile by providing the projectile with a cruising motor which generates a thrust equal to the nominal drag.        
It has been found that a major source of unguided projectile inaccuracy is the jittering of the associated launch tube that is produced at the time of launching. More particularly, launch tube jittering causes the actual launching direction to deviate from the launching direction—hereinafter referred to as a “nominal direction,”—which is generally established by aiming the launch tube in a desired direction. The method proposed by the Davis Gun, as described in U.S. Pat. No. 1,108,717, although providing a reduction in the jittering, has not yet provided satisfactory results.
It is an object of the present invention to provide a method and system for further improving the accuracy of strikes attainable with unguided projectiles, particularly by compensating for inaccuracies that result from barrel jittering or jittering during the projectile firing.
Other objects and advantages of the invention will become apparent as the description proceeds.